Sorry to dampen the drama but...
Minisubs have been operating for many years with no computers whatsoever.
Or simple laptops running whatever version of Windows is compatible with
the sonar display.
The important life-support stuff is partitioned away from all that. And
Stefan, we can go offline to talk about
why losing the display would not impact our ability to exercise control.
Note that by "losing our primary control system" I meant any operational
downtime (sitting in a warehouse)
while I load a new O.S. (not in the sub itself during a dive).
FYI: AUVs have been using Linux as their primary command/control O.S.
for years, the only competition being
Windows. The old days of dedicated realtime OS's like VxWorks or custom
bare metal apps are over, except
for military vehicles or maybe NASA - too expensive, too difficult to
maintain.
Anyway - I'm upgrading to Mint 17.1 now, so hopefully that obviates the
need to build the .deb package.
For those interested, here's a recent promo about the project:
https://www.youtube.com/watch?v=ipAxZoMzFYk
Regards,
- Pete
On 01/07/2015 12:10 PM, Stefan Baur wrote:
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Hash: SHA1
Am 07.01.2015 um 17:42 schrieb Peter Brodsky:
[...]
The network on which I'd run X2GO is completely private - a mix of
perhaps 3 Linux/Windows systems residing on a small submarine.
Could not see the wider world even if we wanted to, unless someone
figures out how to propagate RF through seawater. So security is
not an issue.
[...]
Given all the options... I'll look into upgrading to Mint 17. This
is tricky given the application (losing our primary control system
computer for any length of time is a very bad thing), but perhaps
this is the best long-term solution.
Oh. My. God.
I sure hope you know what you're doing (well, at least
http://www.apl.washington.edu/people/profile.php?last_name=Brodsky&first_name=Pete
seems to indicate so ;-)) and have some sort of backup/emergency
control/failsafe mechanism in place that can make this thing surface
automatically if something goes, forgive me the pun, belly-up.
Especially if it isn't an AUV but a manned submarine. I'd probably be
in for a new pair of pants and underpants if I heard the submarine I'm
on is controlled by a plain off-the-shelf computer and not some
sophisticated machinery with an trimmed down and hardened RTOS with a
watchdog feature and a backup control system based on a different
design in place.
And that's not because I think X2Go is a crappy piece of software (I'm
the X2Go Lead Evangelist after all, I tell people how fantastic X2Go
is all the time), it's because I would never trust a regular operating
system and off-the-shelf hardware for a task where human lives or some
seriously expensive device like an AUV are/is at stake.
That said, if you *do* get X2Go running in that environment, it would
make for one heck of an entry on our success stories Wiki-page! So if
you do succeed, we'd absolutely love to hear back from you!
So, back to the original problem - what does "xhost" say on your
current Mint 15 machines?
And while this isn't exactly X2Go-related - what does the partitioning
of these machines look like? If you have unpartitioned disk space, a
partition you could spare (that's why I usually have a swap partition
large enough to hold a small Linux installation, when changed from
swap to ext, on my machines), or you are using LVM and have sufficient
free space in there and a boot loader that supports booting from a
logical volume, you might want to look into using debootstrap to
install a newer version of your operating system into the available
space, while your current installation is booted. Or, if debootstrap
isn't available for Mint, do a Mint 17 install on another computer,
tar the image, transfer it to a new partition/LV on the Mint 15
machine, and see if you can boot into it. That should minimize downtime.
Feel free to contact me off-list for some options/best practices. My
company eMail address is [email protected].
I can't claim any previous experience with submarine control systems,
but we do have quite a few Linux computers spread across Germany in
more or less remote locations (there's even one that, according to the
staff that's been on-site once to install the machine, can only be
reached via horse drawn sleigh or snowmobile during the wintertime)
where we do need to run upgrades with minimum downtime, and having
someone on-site to perform the upgrade is usually not an option (and
where it is, it tends to get expensive rather quickly), so we've come
up with a few things to avoid that.
At the same time - Mike I'll take you up on your offer to build a
Debian package for me. I am familiar with Git, of course, but have
not built .deb packages.
Usually, this is the place where I would point out that we do have
commercial support offerings for customers with needs like that one
(I'm sure someone would usually offer to build you packages even for
Mint 15 if you paid for it) - but in your case, I would actually have
to check back with our developers if anyone is willing to offer
commercial support or if they're all too worried about liability
issues in case a bug in the code causes you to lose control over the
AUV/submarine ... drowned customers aren't happy customers, if you
know what I mean. ;-)
- -Stefan
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